Solar panel

ABSTRACT

A solar panel comprising a plurality of elongated and flat pipe elements having a first end, a second end and at least one longitudinal and through pipe channel for a heat carrying liquid, wherein the pipe channels are arranged with a height (H) up to 10 mm. the pipe elements are connected to opposite and elongated edge elements. The edge elements are arranged with a longitudinal channel for the heat carrying liquid, wherein the channels in the edge elements are connected to the pipe channels and extend in a direction perpendicular to the pipe channels. The pipe elements are formed with an aperture on opposite sides of at least one pipe channel, and stop devices are connected to the edge elements at selected apertures and extend into the channels of the edge elements to block the channels and guide the heat carrying liquid between the pipe channels.

FIELD OF THE INVENTION

The present invention relates to a solar panel. Solar panels are usedfor collecting thermal energy from sunlight and use it for heating asuitable heating medium, such as a heat carrying liquid. The heatcarrying liquid is circulated through the solar panel, wherein theliquid is heated by the sun and the thermal energy in the heat carryingliquid can be used for heating different types of constructions. Solarpanels are generally used in heating systems, such as domestic hot watersystems but can also be used for heating buildings, swimming pools andsimilar.

PRIOR ART

A plurality of different types of solar panels are known in the priorart. One conventional type of solar panel comprises a conduit in theform of a tube or a hose for a heat carrying liquid, so that the liquidcan circulate through the conduit for collecting energy from sunlight.The conduit can be arranged between a cover plate, such as a glass or aplastic plate, and a base plate, such as a building panel provided withinsulation, absorber and similar.

One type of prior art solar panels comprises flat pipe elements havingchannels for the heat carrying liquid, wherein a height of the channelsis substantially smaller than a width of the channels. A height of thechannels can be below 10 mm. The pipe elements can be formed in steel oraluminium, such as extruded aluminium.

One problem with such prior art solar panels is that they can beexpensive to produce.

Another problem with prior art solar panels is that they are limited inrange of use due to their structure.

SUMMARY OF THE INVENTION

An object of the invention is to avoid the above mentioned problems ofthe prior art and provide a solar panel resulting in efficient heatingof the heat carrying liquid while simultaneously being easy and costefficient to produce and being adaptable according to the desiredconditions of operation.

The present invention relates to a solar panel comprising a plurality ofelongated and flat pipe elements having a first end, a second end and atleast one longitudinal and through pipe channel for a heat carryingliquid, and wherein the pipe channels are arranged with a height up to10 mm, characterised in that the first end of the pipe elements areconnected to a first edge element, and the second end of the pipeelements are connected to an opposite second edge element, that the edgeelements are elongated and arranged with a longitudinal channel for theheat carrying liquid, wherein the channels in the edge elements areconnected to the pipe channels and extend in a direction perpendicularto the pipe channels, that the pipe elements on opposite sides of atleast one pipe channel are formed with an aperture, and that stopdevices are arranged at selected apertures, wherein the stop devicesextend into the channels in the edge elements to block the channels andguide the heat carrying liquid between the pipe channels. The pipeelements can be formed in aluminium, such as extruded aluminiumprofiles. Also the edge elements can be formed in aluminium, such asextruded aluminium profiles. Alternatively, the edge elements can beformed in or provided with a plastic material for insulation. Due to thearrangement of the pipe elements with the apertures, the arrangement ofthe edge elements with the channels and the stop devices interactingwith the apertures to block the channels an efficient and flexible inuse solar panel is provided which can be produced in a simple and costefficient manner and can be used for heating heat carrying liquids fordifferent purposes.

Further characteristics and advantages of the present invention willbecome apparent from the description of the embodiments below, theappended drawings and the dependent claims.

SHORT DESCRIPTION OF THE DRAWINGS The invention will now be describedmore in detail with the aid of embodiment examples and with reference tothe appended drawings, in which

FIG. 1 is a schematic perspective view obliquely from above of a solarpanel according to one embodiment of the present invention, in which aset of pipe elements, a cover plate, an insulating layer, a base plate,edge elements and corner parts of the solar panel are illustratedseparately,

FIG. 2 is a schematic perspective view according to FIG. 1, in which thecover plate, the insulating layer and the base plate have been removed,

FIG. 3 is a schematic perspective view of a part of a pipe elementaccording to one embodiment,

FIG. 4 is a schematic front view of the pipe element of FIG. 3,

FIG. 5 is a schematic view of the pipe elements, edge elements andcorner parts of a solar panel according to one embodiment, in which oneexample of a flow pattern of a heat carrying liquid is illustrated,

FIG. 6 is a schematic view according to FIG. 5, in which one alternativeexample of a flow pattern of a heat carrying liquid is illustrated,

FIG. 7 is a schematic perspective view of a part of a solar panelaccording to one embodiment,

FIG. 8 is a schematic perspective view of a part of an edge elementaccording to one embodiment,

FIG. 9 is a schematic perspective view of a part of an edge elementaccording to one alternative embodiment,

FIG. 10 is a schematic perspective view of a set of pipe elements, afirst edge element, a second edge element and stop devices according toyet another embodiment,

FIG. 11 is a schematic perspective view of a part of the pipe elements,the first edge element and the stop devices according to FIG. 10,

FIG. 12 is a schematic perspective view of a set of pipe elements, afirst edge element, a second edge element and stop devices according toyet another embodiment, and

FIG. 13 is a schematic perspective view of a part of the pipe elements,the first edge element and the stop devices according to FIG. 12.

THE INVENTION

Referring to FIG. 1 a solar panel 10 for collecting sunlight andconverting energy in sunlight to thermal energy of a heat carryingliquid according to one embodiment is illustrated schematically. Forexample, the solar panel 10 is arranged for circulating a conventionalheat carrying liquid, such as water, water in combination with ananti-freezing agent, glycol or similar conventional liquids for thistype of solar panels. By the description of the different components ofthe solar panel also a method for collecting sunlight and convert energyin the sunlight to thermal energy of the heat carrying liquid isevident, and also the use of a device in the form of the solar panel 10as described herein for collecting sunlight and convert energy in thesunlight to thermal energy of the heat carrying liquid.

The solar panel 10 comprises a plurality of elongated and flat pipeelements 11 for conducting the heat carrying liquid in a desired patternthrough the solar panel 10. In the illustrated embodiment the solarpanel 10 comprises eight pipe elements 11 but the solar panel 10 cancomprise any desired number of pipe elements 11. The pipe elements 11are arranged in parallel and in a common plane to form a rectangular orquadratic structure.

The solar panel 10 also comprises a first edge element 12 and a secondedge element 13. In the illustrated embodiment the solar panel 10further comprises a third edge element 14 and a fourth edge element 15and corner parts 16 connecting the edge elements 12-15. A first end ofthe pipe elements 11 are connected to the first edge element 12, whereina second end of the pipe elements 11 are connected to the second edgeelement 13. The pipe elements 11 together with the first and second edgeelements 12, 13 are arranged for circulating the heat carrying liquidthrough the solar panel 10, which is described more in detail below.

In the embodiment of FIG. 1 the solar panel 10 also comprises a coverplate 17 and a base plate 18. The cover plate 17 is permeable tosunlight. For example, the cover plate 17 is formed in a glass orplastic material, such as polycarbonate. For example, the cover plate 17comprises an upper and a lower plate having channels between them,wherein the cover plate 17 is arranged in the form of so calledcorrugated plastic. For example, the cover plate 17 is arranged in a UVresistant plastic material. The base plate 18 is arranged to insulatethe solar panel 10. For example, the base plate 18 is arranged in aglass or plastic material, such as polycarbonate. For example, also thebase plate is arranged as corrugated plastic. For example, the coverplate 17 and the base plate 18 are connected to the edge elements 12-15.In the illustrated embodiment the solar panel 10 also comprises aninsulating layer 18 b, such as an insulation plate. For example, theinsulating layer 18 b comprises an aluminium panel filled with air, suchas aluminium foils connected to each other and having air between them.For example, the insulating layer 18 b is arranged with a thickness upto 10 mm or up to 5 mm. For example, the total thickness of the solarpanel 10, i.e. the height from the outer side of the base plate 18 tothe outer side of the cover plate 17, is up to 60 mm or 50 mm. Forexample, the total thickness of the solar panel 10 is about 50 mm.

In FIG. 2 the pipe elements 11, the edge elements 12-15 and the cornerparts 16 are illustrated without the cover plate 17, the base plate 18and the insulating layer 18 b. As evident more clearly from FIG. 2 theedge elements 12-15 and the corner parts 16 according to the illustratedembodiment are arranged to be connected to each other to form a frameenclosing the pipe elements 11. The first edge element 12 is connectedto the first ends of the pipe elements 11, wherein the second edgeelement 13 is connected to the second ends of the pipe elements 11. Forexample, the third edge element 14 engages a long side of an outermostpipe element 11, wherein the fourth edge element 15 engages a long sideof an outermost pipe element 11 at the opposite side of the solar panel10. For example, the edge elements 12-15 are arranged in aluminium, suchas extruded aluminium. Alternatively, the edge elements 12-15 arearranged in a suitable plastic material. According to yet anotheralternative embodiment the edge elements 12-15 are formed in aluminiumand are provided with an insulating layer of plastics, for example onthe outer sides of the edge elements 12-15. The edge elements 12-15 areconnected to each other, for example, through the corner parts 16, byconventional fasteners, such as screws.

With reference to FIG. 3 and FIG. 4 the pipe elements 11 are arrangedwith a first pipe channel 19 and a second pipe channel 20 for the heatcarrying liquid. Alternatively, the pipe elements 11 are arranged withat least one pipe channel or more pipe channels, such as three or more.The pipe elements 11 form an absorber of the solar panel 10. The pipechannels 19, 20 extend in the longitudinal direction and through thepipe elements 11 from the first end thereof to their opposite secondend. For example, the pipe channels 19, 20 are parallel. For example,the pipe channels are arranged with a height H of up to 10 mm, such as1-10 mm, 5-8 mm, around 6 mm or about 7 mm. The pipe channels arearranged with a width W being substantially greater than the height H.For example, the width W is 20-200 mm or 30-100 mm, such as 30-50 mm oraround 30-35 mm.

The pipe elements 11 are arranged with at least one aperture 21 in theirends, which aperture extends in the longitudinal direction of the pipeelements 11. In the illustrated embodiment the pipe element 11 comprisesa first aperture 21, a second aperture 22 and a third aperture 23,wherein the first pipe channel 19 is arranged between the first andsecond apertures 19, 20, and wherein the second pipe channel 20 isarranged between the second and third apertures 22, 23. For example, theapertures 21-23 are aligned and extend along a common plane. Forexample, the apertures 21-23 are arranged centrally in the verticaldirection of the pipe elements 11. The apertures 21-23 extend inparallel to the pipe channels 19, 20 and to each other. For example, theapertures 21-23 are through and extend between the first end and secondend of the pipe elements 11. The apertures 21-23 are, for example,arranged with a circular cross section. For example, the apertures 21-23are arranged with a diameter of 3-8 mm, 4-6 mm or around 5 mm. The pipeelements 11 are, for example, arranged with a thickness of materialbelow 0.5-2 mm. For example, the pipe elements 11 are arranged with athickness of material of 1-2 mm or 1-1.5 mm. For example, the thicknessof material is greater around the apertures 21-23 than above and belowthe pipe channels 19, 20. For example, the pipe elements 11 are providedwith a black colour.

In the illustrated embodiment a profile or cross section area of thepipe elements 11 is arranged with greater height around the apertures21-23 than at the pipe channels 19, 20 to form an elevation, such asarc-shaped elevations, on the upper and lower sides of the pipe elements11 at the apertures 21-23. Hence, a height at a centre line extendingradially through the apertures 21-23 is greater than a height of thepipe element 11 at the pipe channels 19, 20.

Referring back to the embodiments of FIG. 1 and FIG. 2 the first edgeelement 12 and the second edge element 13 are arranged with openings 24.The openings 24 are through and arranged for receiving a fastener in theform of a screw or similar. Further, the openings 24 are aligned withselected apertures 21-23 in the pipe elements 11, wherein the first andsecond edge element 12, 13 can be connected to the pipe elements 11 by,for example, fastening the first and second edge elements 12, 13 to thepipe elements 11 by screws through the openings 24 and selectedapertures 21-23. For example, the edge elements 12-15 are connected toeach other and with the pipe elements 11 by means of screws, pins, glue,welding, soldering or a combination thereof or in another suitablemanner.

Further, the first and second edge elements 12, 13 are arranged with alongitudinal channel 25 for the heat carrying liquid. The channel 25 isconnected to the pipe channels 19, 20, so that the heat carrying liquidcan flow between the pipe channels 19, 20 and the channel 25 arranged inthe first and second edge elements 12, 13, respectively. The channel 25connects selected pipe channels 19, 20 with each other, such as thefirst and second pipe channels 19, 20 of the same pipe element 11 orpipe channels 19, 20 of adjacent pipe elements 11, which is describedmore in detail below. The channel 25 extends perpendicular to thelongitudinal direction of the pipe channels 19, 20. For example, thechannel 25 extends through the entire length of the first and secondedge elements 12, 13, so that the channel 25 extends from a first end toa second end of the first and second edge elements 12, 13.

The solar panel 10 comprises an inlet 26 for the heat carrying liquid.In the illustrated embodiment the inlet 26 is arranged in a corner part16, so that the heat carrying liquid can be introduced into the channel25 in the first edge element 12, for example through a hole in one endof the first edge element 12, and further into the pipe channels 19, 20in the pipe elements 11. Alternatively, the inlet 26 is arrangeddirectly in the first edge element 12 or in another suitable manner. Forexample, the first edge element 12 is provided with a corresponding hole27 in the opposite end. For example, an outlet 28 for the heat carryingliquid is arranged in another corner part 16 than the inlet 26 in asimilar manner. For example, the outlet 28 is connected to the channel25 of the first or second edge element 12, 13. Alternatively, the outlet28 is arranged directly in the first or second edge element 12, 13.

With reference to FIG. 5 and FIG. 6 different flow structures or flowpatterns of the heat carrying medium in the solar panel 10 areillustrated. The flow between the pipe channels 19, 20 is illustrated bymeans of arrows. As evident from FIG. 5 the solar panel 10 comprisesstop devices 29 for guiding the heat carrying liquid between the pipechannels 11. The stop devices 29 are arranged to be received in thechannel 25 of the first and second edge elements 12, 13, respectively,and to block the channel 25, so that the heat carrying liquid cannotpass the stop device 29 but instead is guided into the pipe channels 19,20. Hence, the stop devices 29 are arranged with a height or diametersubstantially corresponding to a height of the channels 25. Further, thestop devices 29 are, for example, arranged with a length substantiallycorresponding to a width of the channels 25, so that the stop devices 29are arranged with dimensions to substantially correspond to a crosssection area of the channels 25 for blocking them. For example, the stopdevices 29 are arranged in a flexible material, such as a plastic orrubber material. Alternatively, the stop devices 29 are arranged inmetal, such as aluminium. The stop devices 29 are, for example,connected to the pipe elements 11 through the apertures 21-23, whereinstop devices 29 are connected to the pipe elements 11 in selectedapertures 21-23 to provide the desired flow pattern. For example, thestop devices 29 are detachably connectable to the pipe elements 11 atthe apertures 21-23, so that the stop devices 29 can be positioned atthe selected apertures 21-23. In FIG. 5 stop devices 29 in a first endof the pipe elements 11 are arranged at the second aperture 22 of eachof the pipe elements 11 and project into the channel 25 of the firstedge element 12, so that the heat carrying liquid is guided from thesecond pipe channel 20 of a pipe element 11 to the first pipe channel 19of an adjacent pipe element 11 through the channel 25 in the first edgeelement 12. In the second end of the pipe elements 11 stop devices 29are, for example, arranged at the first aperture 21 of each of the pipeelements 11, so that the heat carrying liquid is guided from the firstpipe channel 19 to the second pipe channel 20 of the same pipe element11 through the channel 25 in the second edge element 13.

With reference to FIG. 6 the stop devices 29 in a first end of the pipeelements 11 are arranged at the first or third apertures 21, 23 of everyother pipe element 11, wherein the stop devices 29 in the second end arearranged at the first or third apertures 21, 23 of the remaining pipeelements 11, so that the heat carrying liquid flow in the same directionin two adjacent pipe channels 19, 20 via the channels 25.

With reference to FIG. 7 a part of the pipe elements 11 and a part ofthe first edge element 12 are illustrated according to one embodiment ofthe invention. For example, the second edge element 13 is arranged in acorresponding manner as the first edge element 12. The first edgeelement 12 is arranged with the channel 25 for interaction with the pipechannels 19, 20. In the embodiment of FIG. 7 the channel 25 is open in adirection towards the ends of the first edge element 25. Further, thefirst edge element 12 comprises a first groove 30 for receiving thecover plate 17, and a second groove 31 for receiving the base plate 18.For example, the first edge element 12 also comprises a groove forreceiving the insulating layer 18 b.

In the embodiment of FIG. 7, the stop devices 29 in the first and secondedge elements 12, 13 are arranged with a screw hole 32 for receiving afastener in the form of a screw 33, so that screws 33 can be insertedthrough the openings 24 and be connected with the pipe elements 11through the screw holes 32 arranged in the stop devices 29. Hence, thefirst and second edge elements 12, 13 are connected to the pipe elements11 by means of the screws 33 while the stop devices 29 simultaneouslyare fastened at their apertures 21-23, respectively. For example, thestop devices 29 extend into the apertures 21-23. Alternatively, the stopdevices 29 are arranged between the apertures 21-23 and the first andsecond edge elements 12, 13, respectively, to block the channel 25. Forexample, the screws 33 extend through the stop devices 29 and into theselected apertures 21-23 of the pipe elements 11. For example, the stopdevices 29 also form spacers between an inner wall of the first andsecond edge elements 12, 13 and the pipe elements 11.

With reference to FIG. 8 a part of the first edge element 12 isillustrated according to one embodiment example, in which the first edgeelement 12 is an aluminium profile, such as an extruded aluminiumprofile, with the channel 25, the first groove 30 and the second groove31. In the embodiment of FIG. 8 an end surface 34 is arranged in theends of the first and second edge elements 12, 13 at the channel 25 orat a front portion of the channel 25, for example, to keep the pipeelements 11 in position and prevent lateral displacement thereof, suchas during assembly of the solar panel 10. Alternatively, the first edgeelement 12 is formed without the end surface 34.

With reference to FIG. 9 a part of the first edge element 12 accordingto one alternative embodiment example is illustrated, in which the firstedge element 12 is an aluminium profile, such as an extruded aluminiumprofile, with the channel 25, the first groove 30 and the second groove31. In the embodiment of FIG. 9 the first and second edge elements 12,13 comprise the optional end surface 34. Further, the opening to thechannel 25 is formed after the profile or cross section area of the pipeelements 11. For example, the front opening to the channel 25 is formedwith bores 35 for receiving the material of the pipe elements 11surrounding the apertures 21-23.

With reference to FIGS. 10 and 11 the stop devices 29 and the edgeelements 12, 13 are illustrated according to one alternative embodiment.The pipe elements 11 are arranged in a similar way as described abovewith reference to FIGS. 3 and 4. In the embodiment of FIGS. 10 and 11the openings 24 in the edge elements 12, 13 are arranged for receivingstop devices 29, so that stop devices 29 project through the openings 24and into the channels 25. The stop devices 29 are fastened in thechannels 25 by means of fasteners, such as the screws 33 extendingthrough the screw holes 32 in the stop devices 29. For example, thescrews 33 extend into the selected apertures 21-23 in the pipe elements11 to connect stop devices 29 in the desired positions for guiding theflow through the solar panel 10. The stop devices 29 are, for example,arranged in aluminium and are fastened in the apertures 21-23 of thepipe elements 11 by means of the screws 33. In the embodiment of FIGS.10 and 11 the stop devices 29 are arranged with a flange 36 for sealingengagement with an outer surface of the edge elements 12, 13, so thatthe liquid in the channels 25 does not leak out through the openings 24.

As evident from FIGS. 10 and 11 the openings 24 in the first edgeelement 12 are elongated in the lateral direction for receiving a stopdevice 29 having two screw holes 32 arranged adjacent to each other. Theopenings 24 extend from an outer side of the edge elements 12, 13 to thechannel 25. The screw holes 32 in the stop device 29 are aligned withadjacent apertures 21, 23 of two adjacent pipe elements 11. Hence, thestop device 29 is fastened in two apertures 21, 23 arranged next to eachother by screwing, wherein the stop device 29 and the screws 33 alsoconnect two adjacent pipe elements 11. As evident from FIG. 10 the stopdevices 29 arranged in the channel 25 of the second edge element 13 arearranged with only one screw hole 23 and are, for example, connected tothe centre aperture 22 of each or the selected pipe elements 11 by asingle screw 33. For example, the openings 24 in the second edge element13 are circular for receiving a stop device 29 in the form of a cylinderhaving a flange for engaging the outer surface of the second edgeelement 13.

With reference to FIGS. 12 and 13 the stop devices 29 and the edgeelements 12, 13 are illustrated according to yet another alternativeembodiment. In the embodiment of FIGS. 12 and 13 the edge elements 12,13 are arranged without the openings 24. For example, the edge elements12, 13 are formed with a whole and continuous peripheral outer sidebeing impermeable to water. The stop devices 29 are arranged to bepositioned inside the channel 25 and be connected to the pipe elements11 through the apertures 21-23. For example, the stop devices 29 areformed as rectangular parallelepipeds with or without rounded orbevelled corners. For example, the stop devices 29 are arranged inaluminium. The stop devices 29 are connected to the apertures 21-23 inthe pipe elements 11 by means of fasteners in the form of pins 37. Thepins 37 are introduced into the selected apertures 21-23 and areconnected to the pipe elements 11, for example, through spring action inthe radial direction. For example, the pin 37 is a spring pin, alsocalled tension pin. Hence, one end of the pins 37 are forced into thedesired apertures 21-23, wherein the stop devices 29 are arranged with arecess for receiving an opposite second end of the pins 37. The recessesin the stop devices 29 are, for example, not through but formed with abottom.

As evident from FIGS. 12 and 13 the stop devices 29 for fastening insidethe channel 25 of the first edge element 12 are formed with tworecesses, wherein the stop devices 29 for fastening inside the channel25 of the second edge element 13 are arranged with a single recess.Hence, the stop devices 29 inside the first edge element 12 are fastenedto the pipe elements 11 by means of two pins 37, wherein the stopdevices 29 inside the second edge element 13 are fastened to the pipeelements 11 by means of a single pin 37. Hence, the stop devices 29 inthe first edge element 12 connects two adjacent pipe elements 11 by theadjacent apertures 21, 23 of the pipe elements 11. For example, the stopdevices 29 are introduced into the channels 25 through ends of the edgeelements 12, 13 and are connected with pins 37 arranged in selectedapertures 21-23.

1. A solar panel comprising a plurality of elongated and flat pipeelements having a first end, a second end and at least one longitudinaland through pipe channel for a heat carrying liquid, wherein the pipechannels are arranged with a height (H) up to 10 mm, wherein the firstend of the pipe elements are connected to a first edge element, and thesecond end of the pipe elements are connected to an opposite second edgeelement, the first and second edge elements are elongated and arrangedwith a longitudinal channel for the heat carrying liquid, wherein thechannels in the first and second edge elements are connected to the pipechannels and extend in a direction perpendicular to the pipe channels,the pipe elements on opposite sides of at least one pipe channel areformed with an aperture, and stop devices are connected to the pipeelements at selected apertures, wherein the stop devices extend into thechannels of the edge elements to block the channels and guide the heatcarrying liquid between the pipe channels.
 2. A solar panel according toclaim 1, wherein the channel in the first edge element is continuous andextends between opposite ends of the first edge element, and wherein thechannel in the second edge element is continuous and extends betweenopposite ends of the second edge element.
 3. A solar panel according toclaim 1, wherein the stop devices are detachably connectable to the pipeelements through the apertures.
 4. A solar panel according to claim 1,wherein each of the pipe elements are formed with two parallel pipechannels between which an aperture is arranged.
 5. A solar panelaccording to claim 1, wherein the first and second edge elements areconnected to a third and fourth edge element forming a frame enclosing aset of pipe elements.
 6. A solar panel according to claim 5, wherein theedge elements are connected to each other through corner parts, whereinan inlet for the heat carrying liquid is arranged in a first corner partand is connected to the channel in the first edge element, and whereinan outlet for the heat carrying liquid is arranged in a second cornerpart and is connected to the channel in the first or second edgeelement.
 7. A solar panel according to claim 1, wherein the pipechannels are arranged with a height (H) of 5-8 mm or 7 mm.
 8. A solarpanel according to claim 1, wherein the pipe elements are arranged witha width of 50-500 mm or 80-100 mm.
 9. A solar panel according to claim1, comprising a cover plate covering the pipe elements, and a baseplate, so that the pipe elements extend in a plane between the coverplate and the base plate.
 10. A solar panel according to claim 9,comprising an insulating layer between the base plate and the pipeelements.
 11. A solar panel according to claim 9, wherein the first andsecond edge elements are arranged with grooves for receiving edgeportions of the cover plate and the base plate.